Prosecutors will start work later to clarify the law on assisted suicide after a landmark court victory by a multiple sclerosis sufferer.
Law Lords backed a call by Debbie Purdy, 46 and from Bradford, for formal advice on the legal position of those who help a loved one commit suicide.
Director of Public Prosecutions (DPP) Keir Starmer said interim policy guidance would be issued by September.
Critics say the ruling could pressure people into ending their lives early.
Public consultation
Ms Purdy wanted to know if her husband, Omar Puente, would be prosecuted if he helped her to die at assisted suicide centre Dignitas in Switzerland.
Thursday's ruling does not give him immunity from prosecution, but it does mean that the DPP must now make clear the factors that would be taken into account when deciding whether to take action against relatives in such cases.
The BBC's John Andrew said evidence of a clear financial advantage or improper pressure, for instance, would count against them, while proof of compassionate support would weigh in their favour.

Mr Starmer said he would put the controversial issue out to public consultation before publishing permanent policy next spring.
More than 100 UK citizens have so far ended their lives at Dignitas.
No-one who has accompanied them has ever been prosecuted, although the law says they could potentially face 14 years in prison.
Ms Purdy said the ruling "gives me my life back".
"This decision means that I can make an informed choice, with Omar, about whether he travels abroad with me to end my life because we will know exactly where we stand," she said.
'Huge step'
The group Dignity in Dying, which backed her case, said it was a huge step forward.
"The ruling is significant because it distinguishes between maliciously encouraging someone to commit suicide and compassionately supporting someone's decision to die," chief executive Sarah Wootton said.
But disability rights group expressed their opposition to the Law Lords' decision.

Phyllis Bowman, executive officer of Right To Life, said: "Much as we sympathise with Ms Purdy, we are extremely concerned about the manner in which this will leave the vulnerable - that is the disabled, the sick, and the aged."
She said the group would be consulting its lawyers about what action it could take.
Simon Gillespie, chief executive of the MS Society, said: "Debbie Purdy's victory has pushed MS into the spotlight, but there is far more to living with MS - even in its more severe forms - than planning how to die."
Ms Purdy was diagnosed with primary progressive multiple sclerosis in March 1995. She can no longer walk and is gradually losing strength in her upper body.
She had previously lost challenges in the High Court and Court of Appeal. The Lords ruling was her last chance of success in the UK legal system.

Source: http://news.bbc.co.uk/1/hi/health/8177583.stm